I have some questions about the paper “O(N^3) Measurement Cost for Variational Quantum Eigensolver on Molecular Hamiltonians”.
About the section 8 of this paper, they mentioned that the measurement of [XX, ZZ] can be transferred to [ZI, IZ] by unitary conjugation. So how to classically reconstruct the result of [XX, ZZ] by [ZI, IZ]?
The paper also mentioned that (4^N-1) Pauli strings can be divided into (2^N+1) commuting family and each commuting family only needs one measurement. I wonder what the process to reconstruct the result for each commuting family? Thanks for answering!!!
